Neonatally-induced diabetes: lipid profile outcomes and oxidative stress status in adult rats

Abstract

Background. Experimental models are developed for the purpose of enhancing the understanding of the pathophysiological mechanisms involved in diabetes. Experimental findings lead to the development of treatment strategies to maintain metabolic conditions as close to normal as possible. There are several reports about streptozotocin induced mild diabetes to reproduce type 2 diabetes. However, studies about the interaction among glucose levels, lipid profile, and oxidative stress in these animals remain insufficient. Therefore, this study evaluated these parameters in blood samples from adult Wistar rats treated neonatally with streptozotocin. metHods. Female newborn Wistar rats received streptozotocin (70 mg/kg, i.p.) on the 5 th day of life (n5-STZ). Glycemia was measured in the 3 rd and 4 th month of life. At the end of the 4 th month, blood samples were collected and processed for lipid profile and oxidative stress measurements. results. Glycemia of n5-STZ rats were significantly higher compared to those of control rats (p < 0.05). There was no alteration in levels of total cholesterol, triglycerides, lipid peroxidation (TBARS), SOD activity and GSH-t determination (p > 0.05) in the n5-STZ animals when compared to control group. However n5-STZ animals showed a significant decreased HDL-cholesterol rate (p < 0.05). Conclusion. This streptozotocin-induced diabetes model in rats caused hyperglycemia (120- 360mg/dL), characterizing mild diabetes. This glycemic level led to HDL-lipoprotein alteration, which was not sufficient to impair antioxidant enzyme activities or determination of lipid peroxidation in adult life of rats. Further this experimental investigation contributed to the understanding of different results found in other models for mild/moderate diabetes induction in laboratory animals as well as to a better comprehension of the pathophysiological mechanisms of mild diabetes or hyperglycemia in humans.